Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
  • C09K19/06—Non-steroidal liquid crystal compounds
  • C09K19/08—Non-steroidal liquid crystal compounds containing at least two non-condensed rings
  • C09K19/30—Non-steroidal liquid crystal compounds containing at least two non-condensed rings containing saturated or unsaturated non-aromatic rings, e.g. cyclohexane rings
  • C09K19/3001—Cyclohexane rings
  • C09K19/3028—Cyclohexane rings in which at least two rings are linked by a carbon chain containing carbon to carbon single bonds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C43/00—Ethers; Compounds having groups, groups or groups
  • C07C43/02—Ethers
  • C07C43/20—Ethers having an ether-oxygen atom bound to a carbon atom of a six-membered aromatic ring
  • C07C43/225—Ethers having an ether-oxygen atom bound to a carbon atom of a six-membered aromatic ring containing halogen
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2601/00—Systems containing only non-condensed rings
  • C07C2601/12—Systems containing only non-condensed rings with a six-membered ring
  • C07C2601/14—The ring being saturated

Definitions

• the invention relates to fluorinated cyclohexyl derivatives of formula I, wherein
• the invention was based on the object of discovering new stable liquid crystal or mesogenic compounds which are suitable as components of liquid crystalline media and, in particular, have advantageous values for optical and dielectric anisotropy combined with very favorable elastic properties, low viscosity and high nematogenity.
• fluorinated cyclohexyls of formula I are highly suitable as components of liquid crystalline media.
• they have especially advantageous values of optical and dielectric anisotropy ( ⁇ ⁇ and ⁇ ) and unusually high values for the elastic constants.
• ⁇ ⁇ and ⁇ optical and dielectric anisotropy
• the compounds of the formula I are colourless in the pure state and are liquid crystalline in a temperature range which is favourably placed for electrooptical use. They are very stable towards chemicals, heat and light.
• the invention thus relates to the fluorinated cyclohexyl derivatives of the formula I, to liquid crystalline media with at least two liquid crystalline components, wherein at least on component is a compound of the formulae I and to liquid crystal display devices containing such media.
• R1 is preferably alkyl, alkoxy, oxaalkyl, alkanoyloxy or alkenyl and can exhibit a straight-chain or branched structure.
• Alkyl or alkoxy preferably are straight-chain and have 2, 3, 4, 5, 6 or 7 C atoms. Accordingly they are preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, hoxoxy or heptoxy, also methyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octoxy, nonoxy, decoxy, undecoxy, dodecoxy, tridecoxy or tetradecoxy.
• Alkenyl is preferably straight-chain and has 2 or 10 C atoms.
• Branched groups of this type as a rule contain not more than one chain branching.
• formula I includes both the optical antipodes and racemates as well as mixtures thereof.
• n is preferably 1.
• the compounds of the formula I are prepared by methods which are known per se, sich as are described in the literature (for example in the standard works, such as Houben-Weyl, Methoden der Organischen Chemie [Methods of Organic Chemistry], Georg Thieme Verlag, Stuttgart), and in particular under reaction conditions which are known and suitable for the reactions mentioned. Variants which are known per se and are not mentioned in more detail here can also be used in this connection.
• the starting materials can also be formed in situ, such that they are not isolated from the reaction mixture but are immediately reacted further to give the compounds of the formula I.
• a preferred route for preparation starts from the easily accessible phenol of the formula II which can be obtained according to the following route:
• the route to phenol II is
• the compounds of the formula I are prepared from the precursor II by reacting with chlorodifluoromethane or tetrafluorethylene respectively in the presence of a base.
• liquid crystal media in addition to one or more compounds for formula I the liquid crystal media according to the invention preferably contain 2-40 components and in particular 4-30 components. Liquid crystal media being composed of one or more compounds of formula I 7-25 other components are especially preferred.
• These additional components are preferably chosen from the nematic (monotropic or isotropic) substances; in particular from the classes of azoxybenzenes, benzylideneanilines, biphenyls, terphenyls, phenyl or cyclohexyl benzoates, phenyl or cyclohexyl cyclohexynecarboxylates, phenyl or cyclohexyl cyclohexylbenzoates, phenyl or cyclohexyl cyclohexylcyclohexanecarboxylates, cyclohexylphenylbenzoates, cyclohexylphenyl cyclohexynecarboxylates, cyclohexylphenyl cyclohexylcyclohexanecarboxylates, phenylcyclohexanes, cyclohexylbiphenyls, phenylcycl
• the 1,4-phenylene groups of these compounds may be fluorinated.
• L and U independently from each other denote a bivalent residue selected from the group consisting of -Phe-, -Cyc-, -Phe-Phe-, -Phe-Cyc-, -Cyc-Cyc-, -Pyr-, -Dio-, -G-Phe-, -G-Cyc- and their mirror images; in this compilation of residue Phe denotes unsubstituted or fluorinated 1,4-phenylen, Cyc trans- 1,4-cyclohexylene or 1,4-cyclohexylen, Pyr pyrimidine-2,5-diyl or pyridine-2,5-diyl, Dio 1,3-dioxane-2,5-diyl and G 2-(trans-1,4-cyclohexyl)-ethyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl or 1,3-dioxan
• One of the residues L and U is preferably Cyc, Phe or Pyr.
• U preferably denotes Cyc, Phe or Phe-Cyc.
• the liquid crystal media according to the invention preferably contain one or more components selected from the compounds of formulae 1, 2, 3, 4 and 5 with L and U meaning Cyc, Phe and Pyr, said liquid crystal media further containing at the same time one or more components selected from the compounds of formulae 1, 2, 3, 4 and 5 with one of the residues L and U denoting Cyc, Phe and Pyr and the other residue being selected from the group consisting of -Phe-Phe-, -Phe-Cyc-, -Cyc-Cyc-, -G-Cyc-, said liquid crystal media containing in addition to this optionally one or more components selected from the compounds of formulae 1, 2, 3, 4 and 5 with L and U being selected from the group consisting of -Phe-Cyc-, -Cyc-Cyc-, -G-Phe- and
• R' and R'' are independently from each other alkyl, alkenyl, alkoxy, alkenoxy with up tp 8 carbon atoms. R' and R'' differ from one another in most of these compounds, one of the residues usually being alkyl or alkenyl.
• R'' denotes -CN, -CF3, -F, -Cl or -CS while R' has the meaning indicated in subgroup 1 and is preferably alkyl or alkenyl.
• Other variants of the envisaged substituents in the compounds of formulae 1, 2, 3, 4 and 5 are also customary. Many such substances are commercially available. All these substances are obtainable by methods which are known from the literature or by analogous methods.
• the liquid crystal media according to the invention preferably contain in addition to components selected from subgroup 1 also components of subgroup 2, the percentage of these components being as follows: subgroup 1: 20 to 90 %, in particular 30 to 90 % subgroup 2: 10 to 50 %, in partiuclar 10 to 50 %
• the media according to the invention preferably contain 1 to 40 %, in particular 5 to 30 % of the compounds according to the invention. Media containing more than 40 %, in particular 45 to 90 % of the compounds according to the invention are further preferred.
• the media contain preferably 3, 4 or 5 compounds according to the invention.
• the media according to the invention are prepared in a manner which is customary per se. As a rule, the components are dissolved in one another, advantageously at elevated temperature.
• the liquid crystal media according to the invention can be modified by suitable additives so that they can be used in all the types of liquid crystal display devices. Such additives are known to the expert and are described in detail in the literature (H. Kelker/R. Hatz, Handbook of Liquid Crystals, Verlag Chemie, Weinheim, 1980). For example, it is possible to add pleochroic dyestuffs to prepare colored guest-host systems or substances for modifying the dielectric anisotropy, the viscosity and/or the orientation of the nematic phases.
• C crystalline-solid state
• S smectic phase (the index denoting the type of smectic phase)
• N nematic phase
• CH cholesteric phase
• I isotropic phase. The number being embraced by 2 of these symbols denotes the temperature of phase change.
• the fluoro phenyl (R C5H11, 29.2 g, 0.1 mol) is dissolved in a mixture of dioxan (40 ml), water (25 ml) and NaOH (20.0 g, 0.5 mol) and the solution heated to 70°. Chlorodifluoromethane is bubbled through the stirred reaction mixture until no more gas is absorbed and tlc analysis shows an absence of phenol. The cooled reaction mixture is diluted with water (100 ml) and extracted with dichloromethane (3 x 50 ml), the extracts are washed with water, dried and the solvent distilled off. The crude product is purified by distillation (and/or recrystallization).
• a liquid crystalline mixture consisting of 10,0 % EPCH-5OCF2.F 8,0 % EPCH-6OCF2.F 6,0 % EPCH-7OCF2.F 8,0 % CCP-2OCF3 12,0 % CCP-3OCF3 9,0 % CCP-4OCF3 9,0 % CCP-5OCF3 12,0 % BCH-3F.F 10,0 % BCH-5F.F 5,0 % ECCP-3OCF3 5,0 % ECCP-5OCF3 2,0 % CBC-33F 2,0 % CBC-53F 2,0 % CBC-55F exhibits a high clearing point, a low optical anisotropy and a high value for ⁇ .

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Citations (6)

• 1992
  • 1992-06-27 EP EP92110913A patent/EP0521420A1/de not_active Withdrawn

Patent Citations (6)

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